Future Perfect Continuous Tense

The future perfect continuous � tense is formed with the� future perfect � tense of the verb� to be ( shall / will have been ) +� a present participle (verb + -ing).�

The future perfect continuous tense is used :

to indicate the length of time that an action continues in the future.

Examples:

By tomorrow, my uncle� will have been driving a hearse for fifteen years.
My uncle� will have been researching in Antarctica for exactly ten years next Sunday.

to show an action in progress until an event happens in the future. Here, a time clause is used. The future perfect continuous tense may come either before or after the time clause.

Examples:

By the time he comes home at the end of the year, he� will have been studying overseas for five years.
He� will have been studying overseas for five years by the time he comes home at the end of the year.
(Time clause:� by the time he comes home at the end of the year ; main clause: he will have been studying overseas for five years . A comma is placed at the end of a time clause when the clause comes before the main clause.)